<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>登录</title>
		<link rel="stylesheet" type="text/css" href="css/common.css">
		<link rel="stylesheet" type="text/css" href="css/sign_in.css">
		<meta name="Description" content="666的博客,心随你动!" />
	</head>
	<body>
		<div class="signin_box">
			<p class="sign-title">
				<span>欢迎进入啦啦博客网，请登录</span>
			</p>
			<p class="input-area">
				<label for="username" class="username-label"> 请输入用户名： </label>
				<input id="username" name="username" required="required" type="text" placeholder="例:  王小明" />
			</p>
			<p class="input-area">
				<label for="password" class="password-label"> 请输入密码： </label>
				<input id="password" name="password" required="required" type="password" />
			</p>
			<button type="submit" id="submitbutton" onclick="ifEmpty()">登 录</button>
			<p class="change_link">
				还没有账号？
				<a href="sign_up.html" class="to-register">去注册</a>
			</p>
		</div>
	</body>
	<footer>&copy;2019-2030 啦啦啦</footer>
	<script type="text/javascript">
		function ifEmpty() {
			var username = document.getElementById("username").value;
			var password = document.getElementById("password").value;
			var registerButton = document.getElementById("submitbutton");
			if(username=="" || rePassword=="" || password==""){
				alert("不能为空！");
			}
		}
	</script>
</html>
